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Fencer Vulns
high 8.2

CVE-2021-42073 json

An issue was discovered in Barrier before 2.4.0.

published 2021-11-08 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-29059

cvss
8.2
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 73%
public exploits
0
none known

Summary

An issue was discovered in Barrier before 2.4.0. An attacker can enter an active session state with the barriers component (aka the server-side implementation of Barrier) simply by supplying a client label that identifies a valid client configuration. This label is "Unnamed" by default but could instead be guessed from hostnames or other publicly available information. In the active session state, an attacker can capture input device events from the server, and also modify the clipboard content on the server.

Patch / fix

  • barrier_project barrier 2.4.0
  • barrier openSUSE Tumbleweed 2.4.0-1.1
  • barrier Package Hub 15 SP3, openSUSE Leap 15.3 2.4.0-bp153.2.3.1
  • barrier openSUSE Leap 15.2 2.4.0-lp152.3.6.1

opensuse advisories openSUSE-SU-2024:11633-1openSUSE-SU-2021:1595-1openSUSE-SU-2021:1498-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-42073 updated cvss 8.2

barrier: knowing a valid client name allows information leaks and server manipulation

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.46% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • openwall.com http://www.openwall.com/lists/oss-security/2021/11/02/4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:P/I:P/A:N

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.